PLUGGING A RTURN STYLE REGULATOR

[arcticmopar]

 Probably a stupid question but... would it be ok to use a return style regulator Mallory# 4309 and plug the return port to use in a non return setup? I plan on eventually to  istall a return line when I drop the tank and replace sending unit but would like to drive again this summer.

[MEK-Dangerfield]

I'm not familiar with your regulator, but mine has been plugged for a few year now with no trouble. I have no return line.      I do have a fuel pressure gauge on my fuel line leading to the carb, so I know where I am at on adjusting the regulator.

[arcticmopar]

 Thanks Mike. I figured as much but you never know.

[Chryco Psycho]

you will have to try it & see what happens some regulators will nto funtion correctly without a return

[73EStroker]

Most Mallory return style do not work without the return line. I had the same regulator running 3/8 line in and 1/4" return and still would not work. Mallory 110 pump was pushing too much flow and pressure and the excess pressure ended up at the carb needles and filled every cylinder with liquid fuel as it pushed past the float needles. Spoke with Mallory tech and he said the return line has to be the same size as the supply line. ***** of a time pulling all the plugs and draining fuel from the cylinders plus the oil change due to gas contaminated oil. You need a deadhead style regulator which is not the best setup as the return style setup. Aeromotive make a sturdy one but it is still in the $99 range. When I plumb mine in next weekend I will run a restrictor in the 1/4" return back to the tank by tee off fitting where the 3/8 line enters the input side of the regulator. This keeps the Mallory pump healthy as it continually circulates gas. Also will run 2 pressure guages - one before and one after the regulator.

[Strawdawg]

Most Mallory return style do not work without the return line. I had the same regulator running 3/8 line in and 1/4" return and still would not work. Mallory 110 pump was pushing too much flow and pressure and the excess pressure ended up at the carb needles and filled every cylinder with liquid fuel as it pushed past the float needles. Spoke with Mallory tech and he said the return line has to be the same size as the supply line. ***** of a time pulling all the plugs and draining fuel from the cylinders plus the oil change due to gas contaminated oil. You need a deadhead style regulator which is not the best setup as the return style setup. Aeromotive make a sturdy one but it is still in the $99 range. When I plumb mine in next weekend I will run a restrictor in the 1/4" return back to the tank by tee off fitting where the 3/8 line enters the input side of the regulator. This keeps the Mallory pump healthy as it continually circulates gas. Also will run 2 pressure guages - one before and one after the regulator.

That is really strange as Mallory says the 110 series of pumps do not normally need any regulator because they have an internal bypass in the pump which recirculates excess fuel in order to maintain the spec'd pressure.  This bypass is adjustable if need be.

It sounds like the bypass in your pump is jammed shut to me...see the instructions for removal, etc

Mine works like a charm.

[moper]

Most regulators don't care. But the pumps do. If your pump has an internal by-pass you're fine. If the pump is designed for a by-pass regualtor you cannot plug it as the pump will be damaged and overheat.

[mopar12372]

sell it to me and buy a nonreturn style regulater...
why , the pump will run cooler and youll have less current draw from the electrical system fuel pump will last longer.

[73EStroker]

The Mallory 110 is designed to not have a bypass internal. Mine was useless with the small spring in it set at 5-7PSI. So with mine (forgot to tell you people earlier) I put the hard plug in so it now pumps full pressure and flow. The return style regulator let the pressure through to the carb line after the regulator due to the return line back to the tank not being able to take the excess back. Hence the deadhead I am installing with the small return back to keep fuel flowing around in a loop back to the tank. If you use the Mallory with the bypass then (according to the Mallory tech) you may as well buy a stock pump as you are wasting money using it like that. I still have the bypass reg and may even plumb a 3/8 line back to the tank. Still experimenting.

[Strawdawg]

I am confused...if it is designed not to have an internal bypass, why did they put one in it?   

I understand the higher volume pumps would not work with a small internal bypass, but, the 110 series don't put out that much.  Mine delivers about 5.5 at the carb and the internal bypass works perfectly...pump runs very quietly and never gets hot at all.

Maybe a different tech would have a different comment on the subject?

This site agrees with the type of regulator to use...dead head versus return if you do use one altho I think they were not blocking the internal....  http://www.centuryperformance.com/mallory-fuel-pressure-regulators-selection-spg-81.html

I came across that when trying to determine what to replace my dead Holley with
At any rate, that was a heckuva mess that you went thru and you seem to be more calm that I would have been 

[73EStroker]

 

I am confused...if it is designed not to have an internal bypass, why did they put one in it?

 

I asked the Mallory tech the same question. His response was that people want to buy a Mallory (or other similar brand) but they do not want the hassle of replacing the entire fuel system at the same time. So they make this small fix to compensate and provide a pump that can be added to a stock setup. But he did say they were designed to flow lots of fuel all the time. That is why I want to set mine up with recirc and flow full capacity through the 3/8 line and return to the tank just before the deadhead regulator.

[mopar12372]

the return regulaters are made for high output fuelpumps , i dont see any reason to put a regulater on a 110 anyway. my2c